Stereoscopic video processing device and method, and program

ABSTRACT

A stereoscopic video processing device includes a candidate coordinate range calculation unit configured to calculate a range of candidate coordinates of a display position of a reference point of a two-dimensional object in a screen, a parallax total value calculation unit configured to calculate a total value of parallax values of pixels of a region overlapping the two-dimensional object in the stereoscopic video, for each candidate coordinate, a display position determination unit configured to determine a candidate coordinate having a smallest total value of the parallax values as the display position of the reference point of the two-dimensional object, a maximum value specifying unit configured to specify a maximum value of the parallax values of the pixels of the region overlapping the two-dimensional object in the stereoscopic video, and a parallax setting unit configured to set the parallax of the two-dimensional object displayed in the stereoscopic video.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a stereoscopic video processing deviceand method and a program and, more particularly, to a stereoscopic videoprocessing device and method for constantly displaying a stereoscopicvideo which is natural and readily viewable, and a program.

2. Description of the Related Art

A person stereoscopically recognizes an object using the discrepancy(parallax) between an image captured by the right eye and the left eye.Eyeball rotation changes the convergence angle and a person recognizesthe convergence angle as the distance to the object. The convergenceangle is the intersection angle of sight lines.

Using the characteristics of the human eyes, if two two-dimensionalimages with parallax for the left and right eyes are prepared and arerespectively projected to the left and right eyes, a person has theillusion of a distance from the convergence angle to the object andexperiences a stereoscopic effect. Parallax is the deviation between theleft-eye image and the right-eye image.

Display of the left-eye image and the right-eye image one by one isreferred to as a stereoscopic image and the consecutive change between aplurality of left-eye and right-eye images is referred to as astereoscopic video. A device for displaying these images is referred toas a stereoscopic video display device.

A stereoscopic video display device for alternately displaying aright-eye image and a left-eye image on a display with parallax usingshutter glasses in which a pair of left and right lens units isalternately switched between a projective state and light shieldingstate and controlling the left and right lens units to be alternatelyswitched in the projective state and the light shielding state in thetiming of the switching between the right-eye image and the left-eyeimage such that the switching operation of the shutter glasses isunnecessary has been proposed (for example, see Japanese UnexaminedPatent Application Publication No. 2001-320734).

In a stereoscopic video display device, a two-dimensional object such asGUI or text may be displayed so as to overlap a stereoscopic video. Inthis case, two methods may be largely used. One method is a method ofoverlapping the two-dimensional object fixed on the stereoscopic video(Method A). Method A is mainly used in games or the like.

The other method is a method of divisionally displaying the displayregions of the stereoscopic video and the two-dimensional object (MethodB). Method B is mainly used in subtitles of movies.

SUMMARY OF THE INVENTION

However, in Method A, a protruded portion which is regarded as a mostimportant element in the stereoscopic video may be blocked. In addition,since a convergence angle for viewing the second-dimensional object anda convergence angle for viewing the stereoscopic object are different,when viewing the two-dimensional object of the stereoscopic video,adjustment of the convergence angle is forced such as to cause eyestrainto a viewer.

In Method B, it is necessary to secure an area for the two-dimensionalobject in a screen. To this end, the stereoscopic video may not beefficiently used over the entire screen. In addition, similar to MethodA, since the convergence angles for viewing the two-dimensional objectand the stereoscopic object are different, eyestrain may be caused.

It is desirable to constantly display a stereoscopic video which isnatural and readily viewable.

According to an embodiment of the present invention, there is provided astereoscopic video processing device including: a candidate coordinaterange calculation means configured to calculate a range of candidatecoordinates of a display position of a reference point of atwo-dimensional object in a screen based on a movable region which is apredetermined region for displaying the two-dimensional object on thescreen of a stereoscopic video and a size of the two-dimensional object;a parallax total value calculation means configured to calculate a totalvalue of parallax values of pixels of a region overlapping thetwo-dimensional object in the stereoscopic video, for each candidatecoordinate, if the two-dimensional object is displayed using each of thecandidate coordinates in the range as a reference point; a displayposition determination means configured to determine a candidatecoordinate having a smallest total value of the parallax values as thedisplay position of the reference point of the two-dimensional object; amaximum value specifying means configured to specify a maximum value ofthe parallax values of the pixels of the region overlapping thetwo-dimensional object in the stereoscopic video, if the two-dimensionalobject is displayed using the determined display position as thereference point; and a parallax setting means configured to set parallaxof the two-dimensional object displayed in the stereoscopic video basedon the specified maximum value of the parallax value.

The stereoscopic video signal may have a frame rate per means time, andthe parallax total value calculation means may calculate the total valueof the parallax values specified based on a parallax plane representingparallax of each pixel as information included in a frame of thestereoscopic video signal.

The display position determination means may calculate the total valueof the parallax values of the pixels of the region overlapping thetwo-dimensional object for each candidate coordinate in a plurality offrames for displaying the two-dimensional objects.

The maximum value specifying means may specify the maximum value of theparallax values of the pixels of the region overlapping thetwo-dimensional object in the stereoscopic video, if the two-dimensionalobject is displayed using the determined display position based on theparallax plane of the plurality of frames for displaying thetwo-dimensional object as the reference point.

According to another embodiment of the present invention, there isprovided a stereoscopic video processing method including the steps of:causing a candidate coordinate range calculation means, to calculate arange of candidate coordinates of a display position of a referencepoint of a two-dimensional object in a screen based on a movable regionwhich is a predetermined region for displaying the two-dimensionalobject on the screen of a stereoscopic video and a size of thetwo-dimensional object; causing a parallax total value calculation meansto calculate a total value of parallax values of pixels of a regionoverlapping the two-dimensional object in the stereoscopic video, foreach candidate coordinate, if the two-dimensional object is displayedusing each of the candidate coordinates in the range as a referencepoint; causing a display position determination means to determine acandidate coordinate having a smallest total value of the parallaxvalues as the display position of the reference point of thetwo-dimensional object; causing a maximum value specifying means tospecify a maximum value of the parallax values of the pixels of theregion overlapping the two-dimensional object in the stereoscopic video,if the two-dimensional object is displayed using the determined displayposition as a reference point; and causing a parallax setting means toset parallax of the two-dimensional object displayed in the stereoscopicvideo based on the specified maximum value of the parallax value.

According to another embodiment of the present invention, there isprovided a program for enabling a computer to function as a stereoscopicvideo processing device including: a candidate coordinate rangecalculation means configured to calculate a range of candidatecoordinates of a display position of a reference point of atwo-dimensional object in a screen based on a movable region which is apredetermined region for displaying the two-dimensional object on thescreen of a stereoscopic video and a size of the two-dimensional object;a parallax total value calculation means configured to calculate a totalvalue of parallax values of pixels of a region overlapping thetwo-dimensional object in the stereoscopic video, for each candidatecoordinate, if the two-dimensional object is displayed using each of thecandidate coordinates in the range as a reference point; a displayposition determination means configured to determine a candidatecoordinate having a smallest total value of the parallax values as thedisplay position of the reference point of the two-dimensional object; amaximum value specifying means configured to specify a maximum value ofthe parallax values of the pixels of the region overlapping thetwo-dimensional object in the stereoscopic video, if the two-dimensionalobject is displayed using the determined display position as thereference point; and a parallax setting means configured to set theparallax of the two-dimensional object displayed in the stereoscopicvideo based on the specified maximum value of the parallax value.

According to another embodiment of the present invention, a range ofcandidate coordinates of a display position of a reference point of atwo-dimensional object in a screen is calculated based on a movableregion which is a predetermined region for displaying thetwo-dimensional object on the screen of a stereoscopic video and a sizeof the two-dimensional object; a total value of parallax values ofpixels of a region overlapping the two-dimensional object in thestereoscopic video is calculated for each candidate coordinate, if thetwo-dimensional object is displayed using each of the candidatecoordinates in the range as a reference point; a candidate coordinatehaving a smallest total value of the parallax values is determined asthe display position of the reference point of the two-dimensionalobject; a maximum value of the parallax values of the pixels of theregion overlapping the two-dimensional object in the stereoscopic videois specified if the two-dimensional object is displayed using thedetermined display position as the reference point; and the parallax ofthe two-dimensional object displayed in the stereoscopic video is setbased on the specified maximum value of the parallax value.

According to the present invention, it is possible to constantly displaya stereoscopic video which is natural and readily viewable.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a structure in which human eyesrecognize a stereoscopic video;

FIG. 2 is a diagram showing an example of a right-eye image and aleft-eye image with parallax;

FIG. 3 is a diagram showing an example in which the stereoscopic videoshown in FIG. 2 is observed by a person;

FIG. 4 is a diagram showing an example of an image in which atwo-dimensional object is displayed so as to overlap a stereoscopicvideo using the related art;

FIG. 5 is a diagram showing another example of an image in which atwo-dimensional object is displayed so as to overlap a stereoscopicvideo using the related art;

FIG. 6 is a diagram illustrating a variation in convergence anglebetween sight lines when a stereoscopic video is observed;

FIG. 7 is a block diagram showing a configuration example of astereoscopic video display system according to an embodiment of thepresent invention;

FIG. 8 is a block diagram showing a detailed configuration example of anobject display adjustment unit of FIG. 7;

FIG. 9 is a diagram illustrating a configuration of a frame of astereoscopic video signal;

FIG. 10 is a diagram illustrating information supplied by a GUI signal;

FIGS. 11A to 11J are diagrams showing a parallax total value of a regionoverlapping a GUI of 5 frames obtained at an interval of 1 second;

FIG. 12 is a diagram showing a right-eye plane and a left-eye planegenerated by a parallax adjustment unit of FIG. 8;

FIG. 13 is a flowchart illustrating a GUI synthesis process; and

FIG. 14 is a block diagram showing a configuration example of a personalcomputer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present invention will be described withreference to the accompanying drawings.

First, a stereoscopic video display will be described.

FIG. 1 is a diagram illustrating a structure in which human eyesrecognize a stereoscopic video.

As shown in the figure, a person stereoscopically recognizes an objectusing a discrepancy (parallax) between an image captured by a right eyeand an image captured by a left eye. In the example of FIG. 1, in theimage captured by the right eye and the image captured by the left eye,the same circular object is displayed, but the display positions aredifferent.

In order to focus human sight lines on a target object, eyeballs of theright eye and the left eye rotate. The rotation of the eyeballs changesa convergence angle and a person recognizes a distance to the object bythe convergence angle so as to recognize a stereoscopic video as aresult. The convergence angle is an intersection angle of sight lines.

Accordingly, for example, if a stereoscopic video is displayed on atwo-dimensional display unit, a right-eye image and a left-eye imagewith parallax may be prepared and displayed. For example, as shown inFIG. 2, if the right-eye image and the left-eye image with parallax aresimultaneously displayed on the two-dimensional display unit, atriangular object of the figure may be displayed stereoscopically (forexample, to be protruded from the display unit) by the parallax.

In addition, the right-eye image and the left-eye image are, forexample, overlapped and displayed by red light and blue light and areseparated by glasses with red and blue color filters so as to beobserved by the human right eye and left eye, respectively.

FIG. 3 is a diagram showing an example in which the stereoscopic videoshown in FIG. 2 is observed by a person. As shown in the figure, thesight line of the eye line may be focused on substantially the center ofthe object of the left-eye image and the sight line of the right eye maybe focused on substantially the center of the object of the right-eyeimage. Then, the object appears to be protruded at a position where thesight line of the left eye and the sight line of the right eye denotedby dotted lines of the figure are intersected.

However, a two-dimensional object such as GUI or text may be displayedso as to overlap the stereoscopic video. For example, GUI may bedisplayed on content such as a game or subtitles of movie may bedisplayed.

In the case where two-dimensional object may be displayed so as tooverlap a stereoscopic video, two methods may be largely used. Onemethod is a method of overlapping the two-dimensional object fixed tothe stereoscopic video (Method A). Method A is mainly used in games orthe like.

FIG. 4 is a diagram showing an example of an image in which atwo-dimensional object is displayed so as to overlap a stereoscopicvideo using Method A. In the figure, an object surrounded by a rectangleand an object surrounded by an ellipse are considered as two-dimensionalobjects.

In Method A, as shown in FIG. 4, for example, the two-dimensional objectis displayed at a certain position in the stereoscopic video, ifnecessary. However, in Method A, the two-dimensional object may block aprotruding part having a highest importance degree in the stereoscopicvideo. That is, as in the object shown in FIG. 3, a two-dimensionalobject may overlap a protruding part. To this end, it is difficult toprovide a vigorous stereoscopic video.

If the two-dimensional object blocks the protruding part, a user whoobserves the stereoscopic video has an extremely uncomfortableexperience. That is, since the two-dimensional object is an imagewithout parallax, the user experiences the image that appears to bedisplayed on a screen as per normal (so as not to be protruded). Such atwo-dimensional object is displayed so as to hide the part protrudingfrom the screen.

That is, if the two-dimensional object blocks the protruding part, theuser sees a part of the protruding part of the stereoscopic video thatappears to be depressed and attached to the screen and thetwo-dimensional object that appears to be displayed in that part.

In Method A, the above-described programs are present.

The other method of the case where the two-dimensional object isdisplayed so as to overlap the stereoscopic video is a method ofdivisionally displaying the display regions of the stereoscopic videoand the two-dimensional object (Method B). Method B is mainly used insubtitles of movies.

FIG. 5 is a diagram showing another example of an image in which atwo-dimensional object is displayed so as to overlap a stereoscopicvideo using Method B. In the figure, a top region 51 of the screen isregarded as a region in which the stereoscopic video is displayed and abottom region 52 of the screen is regarded as a region in which thetwo-dimensional object is displayed.

However, in Method B, it is necessary to secure an area for thetwo-dimensional object in the screen. To this end, the stereoscopicvideo may not be efficiently used in the entire screen.

If the two-dimensional object is displayed so as to overlap thestereoscopic video, the user pays attention to both the protruding partof the stereoscopic video and the two-dimensional object. In this case,the user alternately views the videos with different parallax, forexample. However, adjustment of a convergence angle according to a rapidparallax variation causes eyestrain.

For example, as shown in FIG. 6, in a scene in which an object istwo-dimensionally displayed, the eyeballs of the human right eye andleft eye are directed to a direction in which the convergence anglebetween sight lines becomes α. Thereupon, if the scene is changed to ascene in which an object is stereoscopically displayed, the eyeballs ofthe right eye and the left eye rotate such that the convergence anglebetween the sight lines becomes β. Rapid eyeball rotation causeseyestrain.

A convergence angle variation and eyestrain are disclosed in KishiNobusuke et al., Test production of content evaluation system ofbinocular stereoscopic video, video information media journal, 2006,Vol. 60, No. 6 pp. 934-942 and Hiroshi Harashima et al.,Three-dimensional image and human science, Ohmsha, Ltd., 2000.

In both Method A and Method B, it is easy to cause eyestrain asdescribed above.

FIG. 7 is a block diagram showing a configuration example of astereoscopic video display system according to an embodiment of thepresent invention. In the figure, the stereoscopic video display system100 includes a stereoscopic video display device 101 and a display 102.

The stereoscopic video display device 101 includes a stereoscopic videosignal acquisition unit 121 and an object display adjustment unit 122therein.

The stereoscopic video signal acquisition unit 121 includes, forexample, a tuner for receiving a stereoscopic video signal transmittedas a broadcast wave. The stereoscopic video signal acquisition unit 121may include, for example, a drive or the like, which reads astereoscopic video signal recorded on a recording medium such as a DVDor a HDD.

The object display adjustment unit 122 is regarded as a functional blockfor performing a process of synthesizing a previously preparedtwo-dimensional object such as GUI or subtitles with the stereoscopicvideo signal acquired by the stereoscopic video signal acquisition unit121 and displaying the synthesized signal. The detailed configuration ofthe object display adjustment unit 122 will be described later withreference to FIG. 8.

The display 102 includes, for example, a Liquid Crystal Display (LCD)and has a two-dimensional image display region. The user wears, forexample, glasses or the like with a color filter so as to view astereoscopic video displayed on the display 102.

The display 102 includes, for example, a screen or the like and maydisplay a stereoscopic video projected from the stereoscopic videodisplay device 101 on a screen. The stereoscopic video display device101 and the display 102 may integrally configure the stereoscopic videodisplay system 100.

FIG. 8 is a block diagram showing a detailed configuration example of anobject display adjustment unit 122 of FIG. 7. In the figure, the objectdisplay adjustment unit 122 includes a display position adjustment unit141 and a parallax adjustment unit 142 therein.

The display position adjustment unit 141 determines the position where atwo-dimensional object is displayed, for example, if the two-dimensionalobject such as GUI is displayed in a stereoscopic video. The displayposition adjustment unit 141 adjusts and determines the display positionof the GUI or the like at a position which does not overlap a protrudingpart of the stereoscopic video as much as possible.

The display position adjustment unit 141 receives, for example, thesupply of a GUI signal and adjusts the display position of the GUIdisplayed based on the GUI signal.

The parallax adjustment unit 142 applies appropriate parallax to animage such as GUI such that the GUI or the like displayed in thestereoscopic video is protruded along with the protruding part of thestereoscopic video.

This will be described in detail with reference to FIGS. 9 to 12.

FIG. 9 is a diagram illustrating a configuration of a frame of astereoscopic video signal. The stereoscopic video signal is configuredin frame units. FIG. 9 shows information included in one frame of thestereoscopic video signal. The stereoscopic video signal which is asignal for displaying a moving image includes, for example, 60 framesduring 1 second. That is, a stereoscopic video of 1 second may bedisplayed by the stereoscopic video signal of 60 frames.

In the example of FIG. 9, the frame of the stereoscopic video signalincludes a right-eye plane, a left-eye plane and a parallax plane. Inaddition, information such as a frame header or an error detection bitis appropriately inserted into the frame.

The right-eye plane and the left-eye plane are regarded as image data ofone screen displayed on the display 102. In the example of FIG. 9, forsimplification of description, an image of one screen displayed on thedisplay 102 includes 64 (=8×8) pixels and each rectangle of theright-eye plane and the left-eye plane denotes one pixel.

In each of the right-eye plane and the left-eye plane, 64 rectangles arepresent, and “0” or “1” is described in each rectangle. Forsimplification of description, a rectangle, in which “0” is described,of the figure denotes a black pixel and a rectangle, in which “1” isdescribed, of the figure denotes a white pixel.

In the example of FIG. 9, an image in which a white object having 2×5pixels is displayed on a black background is shown, and the right-eyeplane and the left-eye plane are different in the display positions ofthe white object having 2×5 pixels. That is, as described with respectto FIG. 3, an image with parallax is displayed such that the objectappears to be protruded from the screen.

A discrepancy in the display position between the right-eye plane andthe left-eye plane may be specified by the parallax plane. The parallaxplane has 64 rectangles corresponding to the pixels of the right-eyeplane and the left-eye plane and is information indicating by how manypixels the right-eye plane is deviated from the left-eye plane. In theexample of FIG. 9, “2” is described as rectangles of the partscorresponding to the display positions of the white object having 2×5pixels in the right-eye plane. This indicates that the white objecthaving 2×5 pixels of the right-eye plane is deviated from the left-eyeplane to the right by two pixels.

FIG. 10 is a diagram illustrating information supplied by a GUI signal.The GUI signal includes a GUI image to be displayed, a predeterminedregion (referred to as a movable region) in which the GUI will bedisplayed in the screen, and information about a standard displayposition of the GUI. The movable region includes a pixel group having asize equal to or greater than that of the GUI. That is, the GUI may bedisplayed at a plurality of positions within the movable region (thedisplay position of the GUI may move within the region).

In the example of FIG. 10, for simplification of description, the GUIimage is a white rectangular image having 4×2 pixels. A rectangle, inwhich “0” is described, of the figure denotes a black pixel and arectangle, in which “1” is described, of the figure denotes a whitepixel. The size (4×2 pixels) of the GUI may be specified by the GUIimage. The size refers to the number of pixels in a horizontal directionand the number of pixels in a vertical direction.

The movable region is information indicating in which part of the screenincluding 64 (=8×8) pixels the GUI is displayed. In the example of FIG.10, the coordinates of the apexes of the screen including 64 pixels aredenoted by (0, 0), (7, 0), (0, 7) and (7, 7) as two-dimensional XYcoordinates. The rectangles of the pixels corresponding to the movableregion are hatched.

On the assumption that the movable region is a rectangle, the coordinatepositions of the top, bottom, left and right ends of the movable regionare specified by the GUI signal. In the example of FIG. 10, a Y-axiscoordinate of the top of the movable region is 5 (“Top=5”) and a Y-axiscoordinate of the bottom is 7 (“Bottom=7”). In addition, an X-axiscoordinate of the left of the movable region is 0 (“Left=0”) and anX-axis coordinate of the right is 7 (“Right=7”).

The standard display position indicates the default display position ofthe GUI and is, for example, specified by coordinates indicating thereference point of the GUI image. The left upper end of the rectangularGUI is the reference point. In the example of FIG. 10, the coordinate ofthe standard display position is (2, 5).

The GUI is displayed based on such a GUI signal.

The display position adjustment unit 141 acquires the movable region andthe size of the GUI and the standard display position from the GUIsignal and the range of candidate coordinates (x, y) which become thecandidates of the display position of the GUI is calculated by Equation(1).

$\begin{matrix}\left. \begin{matrix}{{R\_ left} \leq x \leq {{R\_ right} - {U\_ width} + 1}} \\{{R\_ top} \leq y \leq {{R\_ bottom} - {U\_ height} + 1}}\end{matrix} \right\} & (1)\end{matrix}$

In Equation (1), R_top, R_bottom, R_left and R_right denote the top,bottom, left and right of the movable region, respectively. In addition,U_width denotes the number of pixels (4, in the example of FIG. 10)corresponding to the width of the GUI image and U_height denotes thenumber of pixels (2, in the example of FIG. 10) corresponding to theheight of the GUI image.

In the GUI signal of FIG. 10, the range of x obtained by Equation (1) is0≦x≦4 and the range of y obtained by Equation (1) is 5≦y≦6.

The display position adjustment unit 141 calculates a sum of parallaxvalues of a region overlapping the GUI, if the GUI is displayed at thatposition with respect to all combinations of candidate coordinates (x,y) in the range of x and y obtained as described above. This is becausethe GUI is displayed in a part in which parallax is not present as muchas possible.

For example, if the GUI of the GUI signal of FIG. 10 is initiallydisplayed in the frame shown in FIG. 9, when the candidate coordinate is(0, 5), the GUI having 4×2 pixels is displayed using the coordinate (0,5) of the parallax plane as the left top. In this case, since theparallax value (2) of the pixel position of the coordinate (3, 5) of theparallax plane and the parallax value (2) of the pixel position of thecoordinate (4, 5) become the parallax values of the region overlappingthe GUI, the sum of the parallax values of the region overlapping theGUI is calculated as 4 (=2+2).

Although the pixel position (for example, pixel positions of (0, 5), (0,6), . . . ) with a parallax value of 0 in the parallax plane is a pixelposition without parallax and thus is not calculated as the parallaxvalue of the region overlapping the GUI in the above description, theparallax value of such a pixel position may be calculated as 0.

The display position adjustment unit 141 similarly calculates a sum ofparallax values of the region overlapping the GUI of a plurality offrames after the frame in which the GUI is initially displayed. This isbecause, in general, the GUI is continuously displayed on the screen forat least several seconds. In the above-described example, for example,in 5 frames including a frame of an image displayed after 1 second ofthe image of the frame shown in FIG. 9, a frame of an image displayedafter 2 seconds, . . . , and a frame of an image displayed after 5seconds, when the candidate coordinate is (0, 5), sums of parallaxvalues of the region overlapping the GUI are respectively calculated.

The display position adjustment unit 141 sums and compares the totalvalues of the calculated sum of the parallax values of the 5 frames foreach candidate coordinate. In the above-described example, as thecandidate coordinates, a total of 10 combinations of (0, 5), (1, 5), . .. , (4, 5), (0, 6), (1, 6), . . . (4, 6) is present. The displayposition adjustment unit 141 calculates the total values of the sums ofthe parallax values of the 5 frames corresponding to the 10 candidatecoordinates and determines a candidate coordinate having smallest totalvalue as a GUI display position after adjustment. In addition, the totalvalues of the sums of the parallax values of 5 frames corresponding tothe candidate coordinates are referred to as parallax total values.

For example, as shown in FIGS. 11A to 11J, the parallax total value iscalculated. FIGS. 11A to 11J show the parallax total values of theregion overlapping the GUI of the 5 frames obtained at an interval of 1second from the frame in which the GUI is initially displayed, if therange of x obtained by Equation (1) is 0≦x≦4 and the range of y is5≦y≦6. As shown in the figure, in this case, 10 candidate coordinatesare present and the regions of the 5 parallax planes corresponding tothe candidate coordinates are shown in FIGS. 11A to 11J.

In FIGS. 11I and 11J, the parallax total values are 1.

Similar to the example of FIGS. 11A to 11J, The display positionadjustment unit 141 determines a candidate coordinate closest to thestandard display position as a GUI display position after adjustment, ifa plurality of candidate coordinates having a smallest parallax totalvalue is present. For example, in the GUI signal shown in FIG. 10, sincethe standard display position is (2, 5), the candidate coordinate (3, 6)corresponding to FIG. 11I becomes a candidate coordinate closest to thestandard display position.

If a plurality of candidate coordinates closest to the standard displayposition is present as the candidate coordinate having a smallestparallax total value, the display position adjustment unit 141determines, for example, one candidate coordinate randomly selected fromthe candidate coordinates as a GUI display position after adjustment.

In this way, the display position adjustment unit 141 determines the GUIdisplay position after adjustment.

After the GUI display position after adjustment is determined by thedisplay position adjustment unit 141, the parallax adjustment unit 142sets the parallax added to the GUI image in the stereoscopic video.

The parallax adjustment unit 142 obtains a maximum value M of a parallaxvalue of a region overlapping the GUI, if the GUI is displayed at theGUI display position after adjustment. For example, if the candidatecoordinate is the position shown in FIG. 11I, since the parallax totalvalue is 1, the maximum value M of the parallax value of the regionoverlapping the GUI becomes 1 when the GUI is displayed at the GUIdisplay position after adjustment.

The parallax adjustment unit 142 synthesizes an image such that the GUIis displayed at the GUI display position after adjustment of theright-eye plane in a frame in which the GUI will be displayed. Inaddition, in the frame in which the GUI is displayed, the parallaxadjustment unit 142 synthesizes an image such that the GUI is displayedat a display position shifted from the GUI display position afteradjustment of the left-eye plane to the right side of the screen by Mpixels. That is, the right-eye plane and the left-eye plane in which theGUI image with parallax is synthesized are generated by the parallaxadjustment unit 142.

The parallax corresponding to M pixels does not have to be added as theparallax of the GUI and, for example, parallax corresponding to thenumber of pixels obtained by multiplying M by a predeterminedcoefficient may be added.

Although the example has been described in which the display positionadjustment unit 141 and the parallax adjustment unit 142 extract andprocess 5 frames at intervals of 1 second as shown in FIG. 11 in theabove description, the interval or the number of frames is not limitedthereto. In addition, the display position adjustment unit 141 and theparallax adjustment unit 142 do not necessarily perform the process ofextracting and processing a plurality of frames and, for example, thedisplay position adjustment unit 141 or the parallax adjustment unit 142may extract and process only one frame.

FIG. 12 is a diagram showing a right-eye plane and a left-eye planegenerated by the parallax adjustment unit 142 if the GUI displayed basedon the GUI signal of FIG. 10 is displayed using the position shown inFIG. 11I as the GUI display position after adjustment in the frame shownin FIG. 9.

The right-eye plane of FIG. 12 overlaps the image of the right-eye planeof FIG. 9 so as to be synthesized such that a white rectangular GUIimage having 4×2 pixels is displayed using the GUI display position (3,6) after adjustment as a left upper end. The left-eye plane of FIG. 12overlaps the image of the left-eye plane of FIG. 9 so as to besynthesized such that a white rectangular GUI image having 4×2 pixels isdisplayed using a position (4, 6) shifted from the GUI display positionafter adjustment to the right side by 1 pixel as the left upper end.

The right-eye plane and the left-eye plane synthesized as described withreference to FIG. 12 are generated with respect to each of the framesfor displaying the GUI. For example, if the GUI is displayed for 10seconds, synthesis is performed such that a GUI image with parallax isoverlapped and displayed on the right-eye plane and the left-eye planecorresponding to 600 (=10×60) frames.

In this way, the image based on the right-eye plane and the left-eyeplane generated by the parallax adjustment unit 142 is output to thedisplay 102.

Thus, the user who observes the display 102 sees the GUI which appearsto be displayed at a position which does not overlap the protruding partof the stereoscopic video as much as possible. The GUI does not appearto be fixed to the screen, but appears to protrude from the screen,along with the protruding part overlapping the GUI.

According to the present invention, for example, it is possible todisplay the GUI at a certain position of the screen. For example, sinceit is not necessary to secure a region for a two-dimensional object inthe screen similar to Method B of the related art, the stereoscopicvideo may effectively use the entire screen.

Since the GUI is displayed at a position which is not superposed on theprotruding part of the stereoscopic video as much as possible, the GUIdoes not block a protruding part having a highest importance degree inthe stereoscopic video. Thus, it is possible to provide a vigorousstereoscopic video. Accordingly, for example, it is possible to solvethe problem of Method A of the related art.

Since parallax is applied such that the GUI appears to protrude from thescreen along with the protruding parts overlapping the GUI, it ispossible to prevent an uncomfortable experience for the user and tosuppress eye strain.

Next, an example of a GUI synthesis process by the object displayadjustment unit 122 of FIG. 7 will be described with reference to theflowchart of FIG. 13.

In step S21, the display position adjustment unit 141 acquires a GUIsignal.

In step S22, the display position adjustment unit 141 specifies themovable region and the size of the GUI based on the GUI signal acquiredin step S21.

In step S23, the display position adjustment unit 141 calculates therange of the candidate coordinates based on the movable region and thesize of the GUI specified in step S22. At this time, for example, therange of the candidate coordinates may be obtained by the calculation ofthe above-described equation (1).

In step S24, the display position adjustment unit 141 calculates aparallax total value with respect to all combinations of candidatecoordinates (x, y) in the range obtained by the process of step S23. Atthis time, for example, as described with reference to FIG. 11, parallaxtotal values corresponding to the candidate coordinates are calculated.

In step S25, the display position adjustment unit 141 determines a GUIdisplay position after adjustment.

At this time, for example, a candidate coordinate having a smallestparallax total value is determined as a GUI display position afteradjustment. In addition, if a plurality of candidate coordinates havinga smallest parallax total value is present, a candidate coordinateclosest to the standard display position is determined as the GUIdisplay position after adjustment. If a plurality of candidatecoordinates closest to the standard display position is present as acandidate coordinate having a smallest parallax total value, forexample, one candidate coordinate randomly selected from among thecandidate coordinates is determined as the GUI display position afteradjustment.

In step S26, the parallax adjustment unit 142 obtains a maximum value Mof a parallax value of a region overlapping the GUI if the GUI isdisplayed at the GUI display position after determined by the process ofstep S25. For example, in the case of the candidate coordinate shown inFIG. 11I, since the parallax total value is 1, when the GUI is displayedat the GUI display position after adjustment, the maximum value M of theparallax value of the region overlapping the GUI becomes 1.

In step S27, the parallax adjustment unit 142 applies parallaxcorresponding to M pixels based on the processed result of step S26 andgenerates a right-eye plane and a left-eye plane in which the GUI imageof the GUI signal acquired by the process of step S21 is synthesized.

At this time, for example, in the frame for displaying the GUI, theimage is synthesized such that the GUI is displayed at the GUI displayposition after adjustment of the right-eye plane. In the frame fordisplaying the GUI, the image is synthesized such that the GUI isdisplayed at a display position shifted from the GUI display positionafter adjustment of the left-eye plane to the right side of the screenby M pixels.

In this way, the GUI synthesis process is executed.

Although the case of synthesizing the GUI to the stereoscopic video hasmainly been described in the above description, subtitles or othertwo-dimensional objects may be synthesized to the stereoscopic video.

Although the case where the parallax plane is included in the frame ofthe stereoscopic video signal has been described, the present inventionis applicable to that the parallax plane is not included in the frame ofthe stereoscopic video signal. If the parallax plane is not included,for example, in the display position adjustment unit 141, by a blockmatching process or the like, the positions of the object of theright-eye plane and the left-eye plane are specified so as to obtain thesame information as the parallax plane.

The above-described series of processes may be executed by hardware orsoftware. If the above-described series of processes is to be executedby software, a program configuring the software is installed in acomputer in which dedicated hardware is mounted from a network or arecording medium. Various programs capable of executing variousfunctions are installed, for example, in a general-purpose personalcomputer 700 or the like shown in FIG. 14 from the network or therecording medium.

In FIG. 14, a Central Processing Unit (CPU) 701 executes variousprocesses according to a program stored in a Read Only Memory (ROM) 702or a program loaded from a storage unit 708 to a Random Access Memory(RAM) 703. In the RAM 703, data necessary for executing the variousprocesses of the CPU 701 is appropriately stored.

The CPU 701, the ROM 702 and the RAM 703 are connected to each otherthrough a bus 704. An input/output interface 705 is connected to the bus704.

An input unit 706 including a keyboard, a mouse and the like, a displayincluding a Liquid Crystal Display (LCD) and the like, and an outputunit 707 including a speaker and the like are connected to theinput/output interface 705. The storage unit 708 including a hard diskand the like and a communication unit 709 including a network interfacecard such as a modem and a LAN card are connected to the input/outputinterface 705. The communication unit 709 performs a communicationprocess over a network including the Internet.

A drive 710 is connected to the input/output interface 705 if necessaryand a removable media 711 such as a magnetic disk, an optical disc, amagnetooptical disc or a semiconductor memory is appropriately mounted.A computer program read from the removable media is installed in thestorage unit 708 if necessary.

If the above-described series of processes is executed by software, theprogram configuring the software is installed from the network such asthe Internet or the recording medium including the removable media 711or the like.

The recording medium includes, for example, as shown in FIG. 14, notonly the removable media 711 including a magnetic disk (including afloppy disk (registered trademark)), an optical disc (including aCompact Disc-Read Only Memory (CD-ROM) or a Digital Versatile Disc(DVD)), a magnetooptical disc (Mini disc (MD)), a semiconductor memoryor the like, in which a program is recorded and which is distributed inorder to deliver a program to a user, the ROM 702 in which a program isrecorded and which is delivered to a user in a state of being assembledin the device body in advance, or the hard disk included in the storageunit 708.

The program executed by the computer may be a program for performingprocesses in time series in the order described in the presentspecification or, although not processed in time series, a program forperforming processes in parallel or individually.

The embodiments of the present invention are not limited to theabove-described embodiments and various modifications are made withoutdeparting from the scope of the present invention.

The present application contains subject matter related to thatdisclosed in Japanese Priority Patent Application JP 2010-036372 filedin the Japan Patent Office on Feb. 22, 2010, the entire contents ofwhich are hereby incorporated by reference.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

1. A stereoscopic video processing device comprising: a candidatecoordinate range calculation means configured to calculate a range ofcandidate coordinates of a display position of a reference point of atwo-dimensional object in a screen based on a movable region which is apredetermined region for displaying the two-dimensional object on thescreen of a stereoscopic video and a size of the two-dimensional object;a parallax total value calculation means configured to calculate a totalvalue of parallax values of pixels of a region overlapping thetwo-dimensional object in the stereoscopic video, for each candidatecoordinate, if the two-dimensional object is displayed using each of thecandidate coordinates in the range as a reference point; a displayposition determination means configured to determine a candidatecoordinate having a smallest total value of the parallax values as thedisplay position of the reference point of the two-dimensional object; amaximum value specifying means configured to specify a maximum value ofthe parallax values of the pixels of the region overlapping thetwo-dimensional object in the stereoscopic video, if the two-dimensionalobject is displayed using the determined display position as thereference point; and a parallax setting means configured to set parallaxof the two-dimensional object displayed in the stereoscopic video basedon the specified maximum value of the parallax value.
 2. Thestereoscopic video processing device according to claim 1, wherein thestereoscopic video signal has a frame rate per means time, and theparallax total value calculation means calculates the total value of theparallax values specified based on a parallax plane representingparallax of each pixel as information included in a frame of thestereoscopic video signal.
 3. The stereoscopic video processing deviceaccording to claim 2, wherein the display position determination meanscalculates the total value of the parallax values of the pixels of theregion overlapping the two-dimensional object for each candidatecoordinate in a plurality of frames for displaying the two-dimensionalobjects.
 4. The stereoscopic video processing device according to claim3, wherein the maximum value specifying means specifies the maximumvalue of the parallax values of the pixels of the region overlapping thetwo-dimensional object in the stereoscopic video, if the two-dimensionalobject is displayed using the determined display position based on theparallax plane of the plurality of frames for displaying thetwo-dimensional object as the reference point.
 5. A stereoscopic videoprocessing method comprising the steps of: causing a candidatecoordinate range calculation means, to calculate a range of candidatecoordinates of a display position of a reference point of atwo-dimensional object in a screen based on a movable region which is apredetermined region for displaying the two-dimensional object on thescreen of a stereoscopic video and a size of the two-dimensional object;causing a parallax total value calculation means to calculate a totalvalue of parallax values of pixels of a region overlapping thetwo-dimensional object in the stereoscopic video, for each candidatecoordinate, if the two-dimensional object is displayed using each of thecandidate coordinates in the range as a reference point; causing adisplay position determination means to determine a candidate coordinatehaving a smallest total value of the parallax values as the displayposition of the reference point of the two-dimensional object; causing amaximum value specifying means to specify a maximum value of theparallax values of the pixels of the region overlapping thetwo-dimensional object in the stereoscopic video, if the two-dimensionalobject is displayed using the determined display position as a referencepoint; and causing a parallax setting means to set parallax of thetwo-dimensional object displayed in the stereoscopic video based on thespecified maximum value of the parallax value.
 6. A program for enablinga computer to function as a stereoscopic video processing devicecomprising: a candidate coordinate range calculation means configured tocalculate a range of candidate coordinates of a display position of areference point of a two-dimensional object in a screen based on amovable region which is a predetermined region for displaying thetwo-dimensional object on the screen of a stereoscopic video and a sizeof the two-dimensional object; a parallax total value calculation meansconfigured to calculate a total value of parallax values of pixels of aregion overlapping the two-dimensional object in the stereoscopic video,for each candidate coordinate, if the two-dimensional object isdisplayed using each of the candidate coordinates in the range as areference point; a display position determination means configured todetermine a candidate coordinate having a smallest total value of theparallax values as the display position of the reference point of thetwo-dimensional object; a maximum value specifying means configured tospecify a maximum value of the parallax values of the pixels of theregion overlapping the two-dimensional object in the stereoscopic video,if the two-dimensional object is displayed using the determined displayposition as the reference point; and a parallax setting means configuredto set parallax of the two-dimensional object displayed in thestereoscopic video based on the specified maximum value of the parallaxvalue.
 7. A stereoscopic video processing device comprising: a candidatecoordinate range calculation unit configured to calculate a range ofcandidate coordinates of a display position of a reference point of atwo-dimensional object in a screen based on a movable region which is apredetermined region for displaying the two-dimensional object on thescreen of a stereoscopic video and a size of the two-dimensional object;a parallax total value calculation unit configured to calculate a totalvalue of parallax values of pixels of a region overlapping thetwo-dimensional object in the stereoscopic video, for each candidatecoordinate, if the two-dimensional object is displayed using each of thecandidate coordinates in the range as a reference point; a displayposition determination unit configured to determine a candidatecoordinate having a smallest total value of the parallax values as thedisplay position of the reference point of the two-dimensional object; amaximum value specifying unit configured to specify a maximum value ofthe parallax values of the pixels of the region overlapping thetwo-dimensional object in the stereoscopic video, if the two-dimensionalobject is displayed using the determined display position as thereference point; and a parallax setting unit configured to set parallaxof the two-dimensional object displayed in the stereoscopic video basedon the specified maximum value of the parallax value.